Abstract:The main characteristics of the general atmospheric circulation in April 2017 are as follows. Double polar vortex centers existed in the Northern Hemisphere, but weaker than usual. The circulation in Eurasian middle high latitude showed a four wave pattern. The strength of Western Pacific subtropical high is stronger than that in normal years. While the south branch trough was almost equal to normal. The monthly mean temperature was 12.0℃, 1.0℃ higher than normal, and the monthly mean precipitation amount was 44.0 mm, which was 2% less than normal. One nationwide strong cold air process happened in this month. There were more precipitation weather events in southern China in this month, with three regional rainstorm processes seen. In addition, two blowing sand weather events happened in the northern China and hail disaster attacked some places of many provinces.